Unilateral Swelling of the Calf or Entire Leg

CLINICAL DIAGNOSTIC MANUAL

Unilateral swelling of the calf or entire leg is a clinical sign that may indicate various underlying pathologies, some of which can be severe and require urgent medical attention.

This condition may result from vascular issues, infections, lymphatic disorders, or congenital abnormalities. Identifying the underlying cause is crucial for appropriate treatment and to prevent potentially life-threatening complications.

Pathology	Suspected Diagnosis	Confirmatory Diagnosis
Deep vein thrombosis (DVT)	Unilateral swelling, pain, warmth, redness, tenderness.	Doppler ultrasound, elevated D-dimer, venography.
Ruptured Baker’s cyst	Swelling and pain in the back of the knee and calf, history of popliteal cyst.	Magnetic resonance imaging (MRI), ultrasound.
Cellulitis	Unilateral swelling, redness, warmth, pain, fever.	Physical examination, skin biopsy, blood cultures.
Lymphatic drainage disorders (lymphoedema)	Chronic swelling, thickened skin, changes in skin texture.	Lymphangiography, ultrasound, MRI.
Congenital oedema	Swelling present since birth or childhood, without other inflammatory symptoms.	Clinical history, ultrasound, genetic testing.